Fire extinguisher



April 25, 1944. J. E. FITZSIMONS 2,347,543

. FIRE EXTlNGUISHER Filed April 7, 1942 4 v INVENTOR. %3Y Z MM! M v m A TTORNEYS.

Patented Apr. 25, 1944 FIRE EXTINGUISHER John Edward Fitzsimons, Westfield, N. J assignor to Pyrene Manufacturing Company, Newark, N. J., a corporation of Delaware Application April '7, 1942, Serial No. 437,957

2 Claims.

This invention relates to fire extinguishers and particularly to pump-type, hand-operated fireextinguishers utilizing liquid halogenated hydrocarbons (for example, carbon tetrachloride or trichlorethylene) as the fire extinguishing medium.

A preferred embodiment of the invention is hereinafter described and illustrated as an improvement upon the type of fire-extinguisher described in Patent No. 1,688,195 assigned to Pyrene Manufacturing Company, the assignee of the present application; but it is obvious that the invention may be embodied in other pump-type, hand-operated fire-extinguishers utilizing a liquid halogenated hydrocarbon as the extinguishing medium, for example, a fire-extinguisher having its handle rigidly instead of slidingly secured to the piston-operating member.

Fire-extinguishers of the above mentioned types are generally characterized by a liquid receptacle having a head carrying a sleeve provided with an opening through which reciprocates a piston-operating member carrying a handle adapted to be locked to said sleeve, resilient sealing means being provided within said handle and surrounding said piston-operating member or cooperation with said sleeve when said handle is locked thereto. In these types of extinguishers, corrosion within the handle has sometimes shortened the life and interfered with proper functioning of the extinguisher.

Such corrosion within the handle of any eX- tinguisher is always objectionable, and it may be particularly objectionable in a type of fireextinguisher in which the piston-operating member and the sealing means carried thereby must be capable of slight reciprocation within the handle when the latter is being locked to or unlocked from the sleeve carried by the head of the liquid receptacle, and said reciprocation may be interfered with by corrosion within the handle. In fire-extinguishers of the type described in the above mentioned patent, the necessary reciprocatory movement of the handle with reference to the piston-operating member and the sealing means carried thereby has been permitted by providing just enough clearance to allow a sliding fit between the handle and piston-operating member to which the sealing means is secured. Ordinarily, the necessary reciprocatory movement of the handle with reference to the piston-operating member and the sealing means properly occurs under all circumstances throughout the life of the extinguisher; and, when the handle is locked to the sleeve in the head of the liquid receptacle, the sealing means ordinarily prevents any halogenated hydrocarbon, either in liquid or gaseous form, from working into the handle.

However, it has been found that, with all types of such extinguishers, the halogenated hydrocarbon, either in liquid or gaseous form, does occasionally get into the cavity in the handle where, due to combination with moisture derived from the atmosphere or otherwise, a halogen acid is formed and causes corrosion of the parts within the handle. This may be due to a variety of causes. For example, if a fire extinguisher of this general type is subjected to excessively high temperatures, expansion of the halogenated hydrocarbon within the receptacle and the creation of pressure therein may cause seepage of the halogenated hydrocarbon past the sealing means and into the cavity in the handle; and of course such seepage is greatly facilitated if the handle has been left unlocked from the sleeve in the head of the extinguisher, or if the extinguisher has been left in a horizontal position or with the handle downward. Such seepage of the halogenated hydrocarbon into the handle also may perhaps occur during an intermission in the pumping of the extinguisher, by creeping of the halogenated hydrocarbon along the piston-operating member and past the sealing means into the cavity in the handle. And such seepage of the halogenated hydrocarbon into the handle may perhaps occur under other conditions. Efforts to prevent such seepage, by improving the sealing means orin other ways, have not been completely successful due, quite probably, to the ability of halogenated hydrocarbon in liquid or gaseous form to pass through the very smallest of spaces.

The present invention is the result of the discovery that corrosion, due to any possible leakage of a halogenated hydrocarbon into the handle of a fire-extinguisher; can be substantially obviated if the cavity withinthe handle, which houses the end of the piston-operating member and the sealing means, is made substantially larger in diameter than the diameters of the piston-operating member or the sealing means or both, thereby providing around those parts a space within said handle, and if said handle is provided with ventilating openings communicating with said space. My belief is that such a construction allows evaporation of any halogenated hydrocarbon which seeps into and is trapped in the handle, before the formation of a halogen 'acid and corrosion can take place. However, the

satisfactory results obtained by this construction were not necessarily to be expected, because it seemed possible that the provision of ventilating accompanying drawing in which Fig. 1 is an elevation, partly in section, of the handle end of .a pump-type, hand-operated fire extinguisher embodying the invention; and Fig. 2 is an elevation of the handle and a portion of the piston-operating member of said extinguisher.

Referring to the drawing, and particularly to Fig. 1, in which the handle 2 of the fire extinguisher is represented in an unlocked position, the receptacle 3 for the halogenated hydrocarbon liquid is shown as provided with a head carrying a sleeve 5 having an Opening therein through which a piston-operating member 6 is adapted to be reciprocated when it is desired to pump the fire extinguishing liquid from the receptacle 3. The piston-operating member has rigidly secured thereon a sealing means 1 adapted to cooperate with the sleeve 5. At its end, the piston-operating member 8 is provided with a spool-shaped head 8 adapted to cooperate with a pin 5 secured in the handle 2, thereby providing for limited reciprocation of the piston-operating member l5 and sealing means 1 Within the handle 2. As shown in Fig. 1, a coiled spring l2 surrounds the piston-operating member 6 between the sealing means and a shoulder within the cavity which receives the piston-operating member 6, the sealing means 1 and the spring l2. The spring I? acts to yieldingly hold the sealing means i and the piston-operating member 5 in the position shown in Fig. 1 when the handle 2 is unlocked from the sleeve 5 in the head l of the extinguisher. When the lugs I3 at the lower end of the handle are forced into engagement with the lock plate is which is a part of the sleeve 5, the spring I2 is compressed and exerts pressure on the sealing means 7 and holds the latter in engagement with the sleeve 5, thereby under ordinary circumstances preventing leakage of liquid from the receptacle 3 and out through the opening in the sleeve 5 through which the pistonoperating member 6 passes.

It will be noted that the axial cavity within the hub of the handle 2, which receives the end of the piston-operating member 6, the sealing means 1 and the spring I2, is of substantially larger diameter than the diameters of said piston-operating member 5 and said sealing means 1 and said spring l2, thereby providing a space within said handle 2 and around said piston-operating member 6 and sealing means I and spring l2. It will also be noted from Figs. 1 and 2 that the hub of the handle 2 is provided with one or more ventilating openings I6 communicating with said annular space. As shown in the drawing, said ventilating openings [6 are in the form of slots extending longitudinally on opposite sides of the hub of the handle 2', but it is obvious that the form of said ventilating openings may be varied. If for any reason any halogenated hydrocarbon seeps into the cavity in the handle 2, it will quickly evaporate through the space within the handle 2 around the piston-operating membar 5 and sealing means 7 and spring l2, and out through the ventilating openings [6 in the handle 2 which communicate with said annular spaces. Therefore, any halogenated hydrocarbon that may seep into the handle evaporates before it can combine with moisture, supplied by the atmosphere or otherwise, to form a halogen acid; and corrosion within the handle is effectively prevented. Thus, the parts within the handle of the fire-extinguisher remain in unimpaired condition even if, for any reason whatever, some halogenated hydrocarbon seeps into the handle.

What is claimed is:

1. In a pump-type hand-operated fire-extinguisher utilizing a halogenated hydrocarbon liquid as a fire-extinguishing medium, the combination of a, piston-operating member and a handle slidingly secured thereto and having a hub provided with an axial cavity into which the end of said piston-operating member extends, the relative size of said cavity and piston-open ating member being such that within said handle there is an annular space around said pistonoperating member, and the hub of said handle being provided with ventilating openings communicating with said annular space.

2. In a pump-type hand-operated fire-extinguisher utilizing a halogenated hydrocarbon liquid as a fire-extinguishing medium, the combination of a piston-operating member and a handle secured thereto and having a hub provided with an axial cavity into which the end of said piston-operating member extends, the relative size of said cavity and piston-operating member being such that within said handle there is an annular space around said piston-operating member, and the hub of said handle being provided with ventilating openings communicating with said annular space.

JOHN EDWARD FITZSIMON S. 

